Q about Phobos regex's architecture

[Nick Sabalausky (Abscissa) via Digitalmars-d]

I'll admit this is a bit unorthodox, but...I've been wondering about 
something regarding Phobos regex's implementation and internal 
architecture: Just how compartmentalized is the parsing of standard PCRE 
regex syntax vs actual usage of regexes once parsed?

Or more to the point, (and again, I realize how unorthodox this is), 
what would it take to implement an alternate (ie, non-PCRE) syntax for 
regexes that still *uses* the rest of the Phobos regex implementation 
once the regex string is parsed?

It is currently coupled enough that the only realistic option is to 
translate the alternate syntax into standard PCRE regex syntax?

Is there a (perhaps "protected", but maybe even "public" if I'm really 
lucky) manual interface to Phobos regex implementation that bypasses the 
PCRE parsing?

Any tips/pointers on where to start with this?